Aggregate signal amplification device and method

ABSTRACT

A surface acoustic wave (SAW) filter that receives an aggregate circuit and outputs two or more sub-signals on outputs each of a different frequency band. The sub-signals are amplified by low noise amplifiers and, in one implementation, the amplified sub-signals can be summed. The outputs are connected via a switched passive network so that portions of the sub-signals on the outputs that are not in the selected frequency band are at least partially terminated.

BACKGROUND

1. Field of the Invention

Embodiments of the invention relate to electronic systems and, inparticular, to radio frequency (RF) electronics.

2. Description of the Related Art

RF electronics, such as cell phones, smart phones, tablets, computers,modems and other devices operate on a limited frequency spectrum.Various schemes are implemented to permit multiple devices to betransmitting and receiving on a particular frequency bandssimultaneously. One such scheme is called carrier or channel aggregationwhich is currently used in 4G LTE Advanced implementations. In thisscheme, wider transmission bandwidths are used to simultaneouslytransmit aggregated component carriers where the component carriers havedifferent frequencies.

The component carriers can either be contiguous or non-contiguousfrequencies. When multiple component carriers in different bands areaggregated and transmitted, they must be received using multiplebandpass filters, one for each band received. Such filters may beentirely independent from one another, or, coupled together at a commoninput point, such as at a common antenna.

Within the wireless receiving device, often the outputs of such filtersmust be amplified and re-combined onto a single path. An example ofwhere this is done in a wireless device is the “diversity” receiver.

However, amplification and combining of these types of signals canresult in significant noise and gain differences for signals among thedifferent received frequency bands, which can affect overall signalquality. Hence, there is a need for an improved system and method ofamplifying aggregated carrier component signals with reduced noise andimproved gain characteristics.

SUMMARY

Certain embodiments disclosed herein provide a device for amplifyingaggregate signals comprising: at least one filter that receives anaggregate signal having a plurality of signal components of differentfrequency bands and separates the aggregate signal into a plurality ofsub-signals of different frequency bands onto a plurality of outputs; aplurality of amplifiers that receive the plurality of sub-signals fromthe plurality of different outputs and amplify the plurality ofsub-signals; and a network interposed between the plurality of outputs,the network having components selected to terminate at least a portionof the signals on the plurality of outputs that have a frequency outsideof the frequency band corresponding to the output.

In one implementation the filter includes a surface acoustic wave (SAW)filter.

In one implementation, the surface acoustic wave (SAW) filter receives adiplex signal and outputs two signals onto two outputs that havedifferent frequencies.

In another implementation the at least one filter includes a pluralityof filters.

In another implementation, the plurality of amplifiers include low noiseamplifiers formed of field effect transistors or bipolar junctiontransistors.

In one implementation the device further comprises a summing componentthat sums the amplified sub-signals.

In one implementation, the summing component includes a common node thatreceives the amplified sub-signals.

In one implementation, the network includes a passive network.

In one implementation, the passive network includes a resistor inparallel with an inductor.

In one implementation, the network includes at least one switch so thatthe passive network is selectively coupled between the plurality ofoutputs when sub-signals are being provided to the plurality of outputsand is selectively disengaged when only a single output signal is beingprovided to one of the plurality of outputs.

In one implementation, the at least one switch includes a plurality ofswitches that are respectively coupled to the plurality of outputs.

Certain embodiments disclosed herein provide a wireless devicecomprising: a receiver that receives wireless signals; a processor thatcontrols the operation of the wireless device; at least one filter thatreceives an aggregate signal having a plurality of signal components ofdifferent frequency bands and separates the aggregate signal into aplurality of sub-signals of different frequency bands onto a pluralityof outputs; a plurality of amplifiers that receive the plurality ofsub-signals from the plurality of different outputs and amplify theplurality of sub-signals; and a network interposed between the pluralityof outputs, the network having components selected to terminate at leasta portion of the signals on the plurality of outputs that have afrequency outside of the frequency band corresponding to the output.

In one implementation, the filter includes a surface acoustic wave (SAW)filter.

In one implementation, the surface acoustic wave (SAW) filter receives adiplex signal and outputs two signals onto two outputs that havedifferent frequencies.

In one implementation, the at least one filter includes a plurality offilters.

In one implementation, the plurality of amplifiers include low noiseamplifiers formed of field effect transistors or bipolar junctiontransistors.

In one implementation, the device further comprises a summing componentthat sums the amplified sub-signals.

In one implementation, the summing component includes a common node thatreceives the amplified sub-signals.

In one implementation, the network includes a passive network.

In one implementation the passive network includes a resistor inparallel with an inductor.

In one implementation, the network includes at least one switch so thatthe passive network is selectively coupled between the plurality ofoutputs when sub-signals are being provided to the plurality of outputsand is selectively disengaged when only a single output signal is beingprovided to one of the plurality of outputs.

In one implementation, the at least one switch includes a plurality ofswitches that are respectively coupled to the plurality of outputs.

In one implementation, the device includes a plurality of filters thatreceive aggregate signals.

Certain embodiments disclosed herein disclose a method of amplifyingaggregate signals comprising: separating onto outputs aggregate signalshaving a plurality of signal components of different frequency bandsinto sub-signals of pre-selected frequency bands; amplifying thesub-signals; and interconnecting the outputs via an impedance network,the impedance network being selected so as to at least partiallyterminate portions of a sub-signal on an output having a frequency otherthan the pre-selected frequency band.

In one implementation, separating the aggregate signals includesseparating the signals using a multiplex surface acoustic wave (SAW)filter.

In one implementation, amplifying the sub-signals includes amplifyingthe sub-signals using a low noise amplifier.

In one implementation, interconnecting the outputs via an impedancenetworks includes interconnecting the outputs via switches and a passivenetwork.

In one implementation, the passive network includes a resistor inparallel with an inductor.

In one implementation, the method further comprises summing theamplified sub-signals.

In one implementation, separating the aggregate signals includesseparating the signals using a plurality of filters to produce aplurality of sub-signals.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic diagram of a wireless device having a receiverhaving a filtering component of the present disclosure.

FIG. 2 is a schematic block diagram of an example wireless or networkdevice that can include one or more of the modules of FIG. 1.

FIG. 3 is a circuit diagram of a diplexing filter and amplifier circuitthat can be used with the low-noise amplifier module of FIG. 1.

FIG. 4 is a schematic block diagram of a diplexing filter and amplifiercircuit with a switchable passive network that can be used with thelow-noise amplifier module of FIG. 1.

FIG. 5 is a schematic block diagram of an array of diplexing filters andamplifier circuits of FIG. 4.

FIG. 6 is a circuit diagram of one implementation of a diplexing filterand amplifier circuit with a switchable passive network.

FIG. 7 is a circuit diagram of another implementation of a diplexingfilter and amplifier circuit with a switchable passive network.

FIG. 8 is a circuit diagram of another implementation of a diplexingfilter and amplifier circuit with a switchable passive network.

FIG. 9 is a circuit diagram of another implementation of a filter andamplifier circuit with a switchable passive network with a plurality offilters.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

FIG. 1 is a schematic diagram of a wireless device 11 such as a cellularphone, smart phone, tablet, modem, communication network or any otherportable or non-portable device configured for voice and/or datacommunication.

The device 11 includes an antenna 14 that receives signals such asmultiplex signal and a filter component 24 that in one specificimplementation derives component signals from a multiplex signal.However, as will be discussed below, the filter component 24 maycomprise any of a number of different filter implementations. Thecomponent further includes a transceiver 13 that can be configured toreceive and transmit signals in a known fashion and a battery 15 thatprovides power to the device 11.

FIG. 2 illustrates the wireless device 11 in greater detail. As shown,the device 11 may receive signals from a plurality of antennas 14including a main antenna, a diversity antenna and the like. The mainantenna 14 may be selected via an antenna switch module 12 so thatsignals can be selectively transmitted and received. The antenna switchmodule 12 receives signals from the transceiver 13 via a power amplifiermodule 17. The transceiver 13 is configured to generate transmit signalsand/or process received signals.

In some embodiments, such transmission and reception functionalities canbe implemented in separate components (e.g. a transmit module and areceiving module), or be implemented in the same module. The antennaswitch module 12 can be configured to switching between different bandsand/or modes, transmit and receive modes etc. As is also shown in FIG.2, the main antenna 14 both receives signals that are provided to thetransceiver 13 via the antenna switch module 12 and also transmitsignals from the wireless device 11 via the transceiver 13, the poweramplifiers 17 and the antenna switch module 12 in a known fashion.

The system of FIG. 2 further includes a power management system 19 thatis connected to the transceiver 13 that manages the power for theoperation of the wireless device. The power management system 19 canalso control the operation of a baseband sub-system 21 and othercomponents of the wireless device 11. The power management system 19provides power to the device 11 via the battery 15 in a known manner.

The baseband sub-system 21 is shown to be connected to a user interface23 to facilitate various input and output of voice and/or data providedto and received from the user. The baseband sub-system 21 can also beconnected to memory 25 that is configured to store data and/orinstructions to facilitate the operation of the wireless device, and/orto provide storage of information for the user.

The power amplifiers 17 can be used to amplify a wide variety of RFsignals. For example, one or more of the power amplifiers 17 can receivean enable signal that can be used to pulse the output of the poweramplifier to aid in transmitting a wireless local area network (WLAN)signal or any other suitable pulsed signal.

Each of the power amplifiers 17 need not amplify the same type ofsignal. For example, one power amplifier can amplify a WLAN signal,while another power amplifier can amplify, for example, a Global Systemfor Mobile (GSM) signal, a code division multiple access (CDMA) signal,a W-CDMA signal, a Long Term Evolution (LTE) signal, or an EDGE signal.

In certain embodiments, a processor can be configured to facilitateimplementation of various processes described herein. For the purpose ofdescription, embodiments of the present disclosure may also be describedwith reference to flowchart illustrations and/or block diagrams ofmethods, apparatus (systems) and computer program products.

It will be understood that each block of the flowchart illustrationsand/or block diagrams, and combinations of blocks in the flowchartillustrations and/or block diagrams, may be implemented by computerprogram instructions. These computer program instructions may beprovided to a processor of a general purpose computer, special purposecomputer, or other programmable data processing apparatus to produce amachine, such that the instructions, which execute via the processor ofthe computer or other programmable data processing apparatus, createmeans for implementing the acts specified in the flowchart and/or blockdiagram block or blocks.

In certain embodiments, these computer program instructions may also bestored in a computer-readable memory 29 that can direct a computer orother programmable data processing apparatus to operate in a particularmanner, such that the instructions stored in the computer-readablememory produce an article of manufacture including instruction meanswhich implement the acts specified in the flowchart and/or block diagramblock or blocks.

The computer program instructions may also be loaded onto a computer orother programmable data processing apparatus to cause a series ofoperations to be performed on the computer or other programmableapparatus to produce a computer implemented process such that theinstructions that execute on the computer or other programmableapparatus provide steps for implementing the acts specified in theflowchart and/or block diagram block or blocks.

As is also shown in FIG. 2, the wireless device 11 can also include afilter and amplifier element 24 that is adapted in one specific instanceto receive a first input signal and filter the signal into one or moreoutput signals and amplify the output signals.

In one specific implementation, the filter and amplifier element 24receives an aggregate carrier or channel signals that comprise componentsignals transmitted on a bandwidth. The element 24 may be part of the RFfront end or may be interposed between the RF front end and thetransceiver 13. Regardless, the element 24 receives, in oneimplementation, a multiplex signal such as a diplex signal that iscomprised of more than one frequency band where the signals areaggregated. This allows for greater transmission of data and signals.Often, the signals will need to be amplified prior to the signals beingused. The implementation shown in FIG. 2 is simply exemplary and shouldbe non-limiting.

More specifically, as shown in FIG. 2 the wireless device 11 may includethe element 24 that receives signals from an antenna 14. The element 24includes a filter 42 such as a multiplex filter that receives anaggregate signal that comprises a plurality of signal components. Thefilter 42 then separates the aggregate signals into the signalcomponents on different frequency bands and provides this to low noiseamplifiers 44 via a network 50 that is preferably switchable.

As will be described in greater detail below, the network 50 is designedto terminate or at least attenuate portions of the component signalsthat fall outside of the frequency band of the component signals toreduce noise and improve signal performance. The output of theamplifiers 44 can then be provided directly to the transceiver 13 or canbe summed via summing component 46.

It should be noted that in FIG. 2, the element 24 is receiving thesignal from a diversity antenna 14. However, the element 24 can alsoreceive signals from a main antenna 14 or can be implemented in any of anumber of different manners without departing from the presentteachings.

FIG. 3 is an exemplary circuit 40 of an amplifier circuit 40 for anaggregated signal. As shown, the circuit 40 includes a filter 42, e.g.,a diplex filter that receives the multiplex signal from, for example,the antenna 14. The diplex filter 42 can comprise, in one non-limitingimplementation, a surface acoustic wave (SAW) filter that receives thediplex signal and outputs two separate signals on two separate frequencybands on outputs 43 a, 43 b. The outputs are then fed into the gate of alow noise amplifying transistor 44 a, 44 b which results in an amplifiedsignal that can then be either provided directly to another circuitcomponent or the amplified signals can be provided to a summing circuitor amplifier 46. The summing circuit 46 can then provide a summed outputsignal.

In one exemplary implementation, the low noise amplifying transistors 44a, 44 b are depicted as FET-type transistors. It will be appreciated,however, that the application should not be limited to simply FET-typetransistors as any of a number of different types of amplifying devicescan be used without departing from the scope of the present disclosure.For example, bipolar junction transistor applications can also be usedwithout departing from the scope of the present teachings.

In one implementation, the summing circuit 46 comprises a common nodethat receives the signals from the transistors 44 a, 44 b but otherimplementations are also possible without departing from the scope ofthe present invention. The multiplex filter 42 can be receiving theinput signal from the antenna 14 or from the RF front end 12 or anyother component and the summing circuit 46 can be providing theamplified signal to the RF front end 12, to the antenna 14 or any othercomponent depending upon the implementation. Again, a person of ordinaryskill in the art will appreciate that the component can be implementedin any of a variety of different configurations of a wireless device.

One difficulty that occurs with the circuit of FIG. 3 is that there canbe substantial noise and difference gain on each of the frequency bandsof the output of the multiplex filter 42. This occurs as a result of thesignals on one band back coupling to the low noise amplifier inputs 44a, 44 b and reflecting at the multiplex signal filter 42 in theaggregated band. This occurs because, at frequencies other than theintended pass bands of the multiplex filter 42, the filter 42 outputsare highly reflective which results in significant gain variation.

Further, the low noise amplifiers will only give low noise figures whenthe source impedance is correctly matched. If the input of the low noiseamplifiers 44 a, 44 b are presented with a very reflective sourceimpedance in the aggregate frequency bands, the output noise of the lownoise amplifier 44 a, 44 b can be very high which degrades circuitperformance.

In order to address these issues, a switchable network 50, such as apassive network, can be implemented between the multiplex filter 42 andthe low noise amplifiers 44 a, 44 b. The switchable network 50 ispreferably tuned so that the network 50 provides for mutual terminationof the portion of the signal that is being reflected. In other words,the portion of the signal on each of the outputs 43 a, 43 b that has afrequency component that falls outside of the band for the output 43 a,43 b is preferably terminated or attenuated by the network 50.

The switchable network 50 can comprise a network of passive components,such as resistors, capacitors and inductors and can also include shuntsetc. or even in some implementations active devices. The network 50 ispreferably tuned so that the portion of a signal on one of the outputs43 that is not the correct frequency band for that output 43 a, 43 b isterminated or at least attenuated by the network 50.

Preferably, the network 50 is switchable such that the network can beselectively connected and disconnected between the two outputs 43. Thispermits the use of either output 43 when a non-aggregate signal is beingpassed by the filter 42 with the losses introduced by the network 50reduced as a result of the network being switched out of the circuit.However, when the filter 42 is passing an aggregate signal on one ormore of the outputs 43, the passive network 50 can be switched betweenthe two outputs 43 thereby allowing the termination of the portion ofthe signals on the outputs that would otherwise cause noise and gaininconsistencies.

FIG. 5 is another implementation of the filter component 24 shown inFIG. 2. As illustrated, the filter component 24 can actually comprise aplurality of circuits components 40 each comprising a multiplex filter42, a switchable passive network 50, amplifiers 44 a, 44 b and summingcomponents 46. Further, the plurality of multiplex filters 42 may alsocomprise multiplex filters 42 that a diplex filters or filters thatreceive aggregate signals having more than two different discrete bandsas demonstrated by the bottom most filter 40 n.

Any other filter or set of filters that have multiple outputs can alsobe used without departing from the spirit of the present teachings.Preferably, there is a switching network 50 n that has multiple passivecomponents such that the unwanted signal components on each of theoutputs 43 can be terminated in the manner described above and theoutputs can be provided to multiple transistors 44 a-44 n. The exactconfiguration of the filter component 24 can vary depending upon theimplementation.

FIG. 6 is a specific exemplary circuit implementation of a filtercomponent 40 that includes a SAW filter 42 having two outputs 43 a, 43 bthat drive the gate of transistors 44 a, 44 b that function as low noiseamplifiers. The drains of the transistors 44 a, 44 b are provided to asumming circuit 46 which, as discussed above, can comprise a common nodethat is connected to each transistor 44 a, 44 b.

In this implementation, the switching passive network 50 comprises aresistor R1 in parallel with an inductor L1 that is connected to theoutputs 43 a and 43 b via switches that are controllable via theprocessor 20 or control 18 (See, FIG. 2). When an aggregate signalhaving two frequency bands is received by the SAW 42, the SAW 42 outputsdiscrete signals on the outputs 43 a, 43 b.

To amplify both signals, transistors 44 a and 44 b are both enabled. Anundesired effect occurs where the signal of each band back-couples tothe opposite-band low noise amplifier input, and reflects off the portof the opposite-band filter of the multiplex filter 42, thereby causingsome signal power to be added or subtracted from the original signal.This results in significant gain variation. To correct this, theswitches S1 and S2 are closed and the parallel resistor and inductornetwork terminates or reduces the unwanted reflected signal component.

Notably, the network does not substantially terminate the desiredforward signal component, because the opposite end of the network istied to the reflective impedance presented by the opposite-band filterport. Effectively the network appears as a tuning stub to the desiredforward signal component. Therefore any excess loss of the desiredsignal is minimized. This results in a cleaner signal being provided tothe amplifiers 44 a, 44 b and to the sum circuit component 46.

In circumstances where the SAW 42 is not providing an aggregate signal,the switches can be disabled so that the losses on the transmission ofthe non-aggregate signal to the low noise amplifiers 44 a, 44 b can bereduced.

FIGS. 7 and 8 further illustrate other implementations. In theimplementation of FIG. 7, an impedance match network comprising aninductor L2 and L3 may be added between the low noise amplifiers 44 a,44 b and the switches S1 and S2 so as to provide the best possible noisefigure for the amplifiers 44 a, 44 b. Similarly, in FIG. 8, inductors L4and L5 can also be added between the switches S1 and S2 and the SAW 42for the same purpose. The switched network 50 can thus be implementedeither before or after the matching components that are selected toreduce the noise figure for the amplifiers 44 a, 44 b.

FIG. 9 illustrates that the noise and gain problems discussed above inconjunction with FIG. 3 may also be present if two entirely separatefilters 42 are used. As shown in FIG. 9, two separate filters 42 provideoutputs 43 a, 43 b and the outputs are connected via a switching network50 in the same manner as described above. To the extent that there arecomponents on one of the outputs 43 a, 43 b of the separate filters 42that are not within the frequency band for the output 43 a, 43 b, theswitchable network 50 can be used to terminate those unwanted signals tolower noise and improve gain difference between the outputs.

As preceding discussion has provided example implementations describedin connection with SAW devices. However, it should be appreciated thatany filter or set of filters, irrespective of construction, may presentan unterminated impedance to the circuit out of their respective passband. As such the output 43 a, 43 b may be receiving outputs ofdifferent types of filters and the unterminated impedances can similarlybe terminated by an appropriately designed switchable network 50 withinthe scope of the present disclosure.

While the foregoing has shown, illustrated and described variousimplementations and uses of the present invention, a person of ordinaryskill in the art will appreciate that various changes, substitutions andmodifications to the embodiments described herein can be made by thoseskilled in the art without departing from the scope and spirit of thepresent invention. Hence, the present invention should not be limited tothe foregoing descriptions but should be defined by the appended claims.

What is claimed is:
 1. A device for amplifying aggregate signalscomprising: at least one filter that receives either an aggregate signalhaving a plurality of signal components of different frequency bands andseparates the aggregate signal into a plurality of sub-signals ofdifferent frequency bands onto a plurality of outputs or annon-aggregate signal having a single signal component that is providedto at least one of the plurality of outputs; a plurality of amplifiersthat are connected to the plurality of outputs to receive the pluralityof sub-signals from the plurality of different outputs and amplify theplurality of sub-signals; and a network connected between the pluralityof outputs, the network having components selected to terminate at leasta portion of the signals on the plurality of outputs that have afrequency outside of the frequency band corresponding to the output thenetwork being switchable between a first configuration where the networkcomponents are terminating at least a portion of the signals on theplurality of outputs when an aggregate signal is received and a secondconfiguration where the network components are not terminating at leasta portion of the signal on the plurality of outputs when a non-aggregatesignal is received.
 2. The device of claim 1 wherein the filter includesa surface acoustic wave (SAW) filter.
 3. The device of claim 2 whereinthe surface acoustic wave (SAW) filter receives a diplex signal andoutputs two signals onto two outputs that have different frequencies. 4.The device of claim 2 wherein the at least one filter includes aplurality of filters.
 5. The device of claim 1 wherein the plurality ofamplifiers include low noise amplifiers formed of field effecttransistors or bipolar junction transistors.
 6. The device of claim 1further comprising a summing component that sums the amplifiedsub-signals.
 7. The device of claim 6 wherein the summing componentincludes a common node that receives the amplified sub-signals.
 8. Thedevice of claim 1 wherein the network includes a passive network.
 9. Thedevice of claim 8 wherein the passive network includes a resistor inparallel with an inductor.
 10. The device of claim 8 wherein the networkincludes at least one switch so that the passive network is selectivelycoupled between the plurality of outputs when sub-signals are beingprovided to the plurality of outputs and is selectively disengaged whenonly a single output signal is being provided to one of the plurality ofoutputs.
 11. The device of claim 10 wherein the at least one switchincludes a plurality of switches that are respectively coupled to theplurality of outputs.
 12. A wireless device comprising: a receiver thatreceives wireless signals; a processor that controls the operation ofthe wireless device; at least one filter that receives either anaggregate signal having a plurality of signal components of differentfrequency bands and separates the aggregate signal into a plurality ofsub-signals of different frequency bands onto a plurality of outputs ora non-aggregate signal having a single signal component that is providedto at least one of the plurality of outputs; a plurality of amplifiersthat are connected to the plurality of outputs to receive the pluralityof sub-signals from the plurality of different outputs and amplify theplurality of sub-signals; and a network connected between the pluralityof outputs, the network having components selected to terminate at leasta portion of the signals on the plurality of outputs that have afrequency outside of the frequency band corresponding to the output thenetwork being switchable between a first configuration where the networkcomponents are terminating at least a portion of the signals on theplurality of outputs when an aggregate signal is received and a secondconfiguration where the network components are not terminating at leasta portion of the signal on the plurality of outputs when a non-aggregatesignal is received.
 13. The device of claim 12 wherein the filterincludes a surface acoustic wave (SAW) filter.
 14. The device of claim13 wherein the surface acoustic wave (SAW) filter receives a diplexsignal and outputs two signals onto two outputs that have differentfrequencies.
 15. The device of claim 12 wherein the at least one filterincludes a plurality of filters.
 16. The device of claim 12 wherein theplurality of amplifiers include low noise amplifiers formed of fieldeffect transistors or bipolar junction transistors.
 17. The device ofclaim 12 further comprising a summing component that sums the amplifiedsub-signals.
 18. The device of claim 17 wherein the summing componentincludes a common node that receives the amplified sub-signals.
 19. Thedevice of claim 12 wherein the network includes a passive network. 20.The device of claim 19 wherein the passive network includes a resistorin parallel with an inductor.
 21. The device of claim 19 wherein thenetwork includes at least one switch so that the passive network isselectively coupled between the plurality of outputs when sub-signalsare being provided to the plurality of outputs and is selectivelydisengaged when only a single output signal is being provided to one ofthe plurality of outputs.
 22. The device of claim 21 wherein the atleast one switch includes a plurality of switches that are respectivelycoupled to the plurality of outputs.
 23. The device of claim 12 whereinthe device includes a plurality of filters that receive aggregatesignals.
 24. A method of amplifying aggregate signals comprising:receiving either aggregate signals having a plurality of signalcomponents having different frequency bands or non-aggregate signalshaving a single signal component separating onto outputs aggregatesignals having a plurality of signal components of different frequencybands into sub-signals of pre-selected frequency bands; amplifying thesub-signals; and selectively interconnecting the outputs via animpedance network, the impedance network being selected so as to atleast partially terminate portions of a sub-signal on an output having afrequency other than the pre-selected frequency band when an aggregatesignal is received; and disconnecting the outputs via the impedancenetwork when a non-aggregate signals is received.
 25. The method ofclaim 24 wherein separating the aggregate signals includes separatingthe signals using a multiplex surface acoustic wave (SAW) filter. 26.The method of claim 24 wherein amplifying the sub-signals includesamplifying the sub-signals using a low noise amplifier.
 27. The methodof claim 24 wherein interconnecting the outputs via an impedancenetworks includes interconnecting the outputs via switches and a passivenetwork.
 28. The method of claim 27 wherein the passive network includesa resistor in parallel with an inductor.
 29. The method of claim 24further comprising summing the amplified sub-signals.
 30. The method ofclaim 24 wherein separating the aggregate signals includes separatingthe signals using a plurality of filters to produce a plurality ofsub-signals.